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    <script>
        // js是编程语言 有很强的逻辑性在里面；实现这个要求的思路 先怎么做 后怎么做
        // 1.我们需要一个临时变量 temp
        // 2.把apple1给到temp
        // 3.把apple2给到apple1
        // 4.把temp（临时变量里边的值）给到apple2
        var temp;//声明了一个临时变量为空
        var apple1 = '青苹果'
        var apple2 = '红苹果'
        temp = apple1//把右边的给左边
        apple1 = apple2
        apple2 = temp
        console.log(apple1)
        console.log(apple2)
    </script>
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